Often, studies require study

False alarms: Raw findings on everything from suicide to breast implants have tempted many to draw concrete conclusions.

April 04, 2004|By Ronald Kotulak | Ronald Kotulak,CHICAGO TRIBUNE

What are people to make of studies suggesting that antidepressants may increase the risk of suicide in adolescents, that breast enhancement surgery may also make some women more prone to kill themselves, or that antibiotics may increase the chance of breast cancer?

Well, scientists themselves don't know what to make of them. After all, these kinds of studies are intended to look for red flags when they find associations between drugs and other medical interventions and adverse side effects. But often the red flags turn out to be false alarms.

Scientists know this but they don't know how to convey the process to the public without first causing unnecessary alarm, especially when an eager, competitive news media runs with the findings without emphasizing that the results are preliminary and need to be verified.

The crux of the problem is that an association between two things may look convincingly as if one leads to the other, but it could also be purely coincidental. It takes rigorous research to determine whether an association is simply happenstance or cause and effect.

Take breast implants. Several recent studies indicate that women who have them are two to three times more likely to commit suicide than women in the general population. It seems to make sense. Women desperately seek breast enhancement because they are extremely unhappy with their body image. But when the implants don't improve their lives, they give up hope.

A convenient explanation, but probably wrong.

When Florida State University psychologist Thomas Joiner looked at the association between implants and suicide he found that breast enhancement may actually reduce the risk of suicide in this population of women.

Women have implants tend to have risky lifestyles. They are more likely to smoke, drink alcohol, have low self-esteem and be divorced, factors that would normally increase their suicide risk to four times the general population, Joiner says.

"I don't think it has much to do with the breast augmentation procedure at all," he says.

Scientists generally conduct three types of studies.

The easiest and fastest is the epidemiological study in which researchers look at a population to see whether they can make a connection between a drug and a bad reaction. This type of study causes the most trouble because the broad net it casts can pull in all kinds of associations that may or may not be genuine.

The second is an open trial in which a drug is given to patients to see what happens. But researchers don't really know if any benefit was because of the drug or because of the body's natural healing powers.

To find the truth, scientists turn to the "gold standard," a randomized double blind placebo controlled trial, which is costly and harder to conduct. It means that people are randomly assigned to a drug or a dummy pill without knowing. The idea is that if people taking a drug get better than those on the dummy pill, the drug is effective.

But even this type of study has a serious weakness. When placebos or dummy pills were first used they were thought to have no effect on the brain or body. But research has shown that the suggestive power of placebos can affect the physiology of the body almost as much as potent drugs.

Placebo power

Brain scans show that when placebos ease pain and lift depression they produce a similar affect on the brain as pain killers or antidepressants, making it difficult to assess the benefit of a new drug.

"When you put patients into studies, for whatever reason, a certain number of them get better who are just assigned to placebo," says Dr. Russell G. Katz, chief of neuropharmacology for the Federal Food and Drug Administration. "Nobody knows exactly why that is but probably they get increased care and contact with medical providers. And the brain does funny things."

Nevertheless, the clinical trial is the best tool scientists have for getting as close as possible to the truth after a population study has found an indication of a drug's potential benefit or harm.

No simple solution

"Rarely do we find definitive answers to specific questions," says Mark A. Reinecke, chief of psychology at Northwestern University Medical School. "This is a situation where the data and the questions are quite complex. They don't lend themselves to simple sorts of bullet point answers, which people want."

"A parent with a youngster who's depressed wants to know what's the take home message," says Reinecke, who is part of a national team of experts studying the safety of antidepressants in adolescents. "Will an antidepressant make him better or worse? But the answers are far more complex and nuanced than that.

"As scientists and parents we have to be tolerant of ambiguity. We can't demand simple answers," he says. "Science evolves over time as new information and new interpretative approaches are brought to bear."

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